Delta Tub Spout Stub Length

I recently installed a Delta tub/shower faucet and it has a slip on spout that tightens with a set screw. The instructions say to "refer to the instructions included with the spout" but there was no such thing included, and I noticed an issue with the spout after installing it. What happens is I turn the water on and the flow is pretty rough from the spout, and some water seems to spray on the tile below the spout because of the rough flow. I was thinking maybe this has something to do with the length of the copper stub coming out from the wall but I'm not sure because Delta's instructions didn't mention any minimum or maximum stub length anywhere in the manual or even on their website from what I saw. Anybody know the Delta specs for the stub with a slip on spout? What I did was measure the internal depth and cut the stub just a bit less than that amount - could it be too long and have the rough flow effect? Delta's customer service has been less than ideal last time I called them so I try to avoid doing that again, but some other brands specify somewhere around 2 7/8" as the maximum stub length. Thanks for any help. It's just frustrating to see water spraying a bit backward towards the opening in the tile, and I wouldn't want to have any water damage within the wall if water gets back in there.

spout

Usually the pipe is the proper length if the spout goes on it and still touches the wall. If your water splashing, and I cannot tell from here why it is happening, were to cause a leak, then you would have that leak and any damage anyway.

Delta Faucet RP5834 1/2" CHROME TUB SPOUT, 5-5/8" x 2-1/2"

I was thinking that the length was fine because the spout did touch the tile as it should, but the instructions don't mention a length for that at all. I looked up into the diverter and it halfway covers the opening where the water comes out so I don't know if that has anything to do with it but it just seems to splash backward a little bit when it's running full blast. I tried it again last night and it wasn't so bad but most spouts I've seen have a nice smooth flow. The opening at the bottom of the spout is pretty wide and almost rectangular if that has anything to do with it.